Leading edge technologies require high performance operation at low-power. Epitaxial growth of silicon germanium carbon (often signified by any of “Si(Ge)(C),” “SiGe(C)” or “SiGe:C”) layers can be an attractive solution to boost device performance. However n-channel metal oxide semiconductor (NMOS) and p-channel MOS (PMOS) transistors within complementary MOS (CMOS) designs require different epitaxies, creating challenges in protecting one type of transistor while performing epitaxy on the other transistor type. Conventional methods require patterning and the use of additional spacers on either NMOS or PMOS devices, which degrades device performance, makes integration very difficult, and leads to defects on the resulting circuits.
There is, therefore, a need in the art for an improved process for the epitaxial deposition of silicon germanium carbon layers during fabrication of CMOS integrated circuits.